title: Optimal parameters of transcranial electrical stimulation for intraoperative monitoring of motor evoked potentials of the tibialis anterior muscle during pediatric scoliosis surgery.
abstract: OBJECTIVE
  Transcranial electric stimulation elicited muscle motor evoked potentials (TESmMEPs) is one of the best methods for corticospinal tract's function monitoring during spine and spinal cord surgeries. A train of multipulse electric stimulation is required for eliciting TESmMEPs under general anaesthesia. Here, we investigated the best stimulation parameters for eliciting and recording tibialis anterior's TESmMEPs during paediatric scoliosis surgery.
  
  
  METHODS
  Numbers of pulses (NOP), inter-stimulus intervals (ISI) and current intensities allowing the best size tibialis anterior muscle's TESmMEPs under general anaesthesia, were tested and collected during 77 paediatric scoliosis surgery monitoring procedures in our hospital. Individual pulse duration was kept at 0.5 ms and stimulating electrodes were positioned at C1 and C2 (International 10-20-EEG-System) during all the tests.
  
  
  RESULTS
  The NOP used for eliciting the best tibialis anterior TESmMEPs response was 5, 6, and 7 respectively in 21 (27%), 47 (61%) and 9 (12%) out of the 77 patients. The ISI was 2, 3 and 4 ms respectively in 13 (17%), 55 (71%) and 9 (12%) of them. The current intensity used varied from 300 to 700 V (mean: 448±136 V).
  
  
  CONCLUSIONS
  Most patients had 6 as best NOP (61%) and 3 ms as best ISI (71%). These findings support that a NOP of 6 and an ISI of 3 ms should be preferentially used as optimal stimulation settings for intraoperative tibialis anterior muscle's TESmMEPs eliciting and recording during paediatric scoliosis surgery.
authors.affiliation: Inserm CIC-IT 805, EA 4497 GRCTH, service de physiologie-explorations fonctionnelles, université de Versailles Saint-Quentin, hôpital Raymond-Poincaré, Assistance publique-Hôpitaux de Paris, 104, boulevard Raymond-Poincaré, 92380 Garches, France; Service epilepsie sommeil et explorations fonctionnelles neuropédiatriques, HFME, université Lyon 1, hospices civils de Lyon, 59, boulevard Pinel, 69003 Lyon, France. Electronic address: eric.azabou@rpc.ap-hop-paris.fr.
authors.forename: E
authors.initials: E
authors.lastname: Azabou
authors.forename: V
authors.initials: V
authors.lastname: Manel
authors.forename: N
authors.initials: N
authors.lastname: Andre-obadia
authors.forename: C
authors.initials: C
authors.lastname: Fischer
authors.forename: F
authors.initials: F
authors.lastname: Mauguiere
authors.forename: C
authors.initials: C
authors.lastname: Peiffer
authors.forename: F
authors.initials: F
authors.lastname: Lofaso
authors.forename: J L
authors.initials: JL
authors.lastname: Shils
mesh_terms: D000293:Adolescent; D002648:Child; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D016343:Monitoring, Intraoperative; D018482:Muscle, Skeletal / Q000502:physiology; D011712:Pyramidal Tracts / Q000502:physiology; D012600:Scoliosis / Q000601:surgery*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D055815:Young Adult
keywords: Children; Chirurgie de la scoliose; Enfants; Intraoperative neurophysiologic monitoring; Motor evoked potential; Paramètres de stimulation; Potentiel évoqué moteur; Scoliosis surgery; Stimulation parameters; Surveillance peropératoire neurophysiologique